Table 1.

Changes in plasma glucose levels and insulin secretion rates during bed rest and exercise studies at different times of 24-h cycle

Rest Exercise P Level
Glucose
 Baseline level, mg/dl
  Afternoon109.8 ± 4.5 106.1 ± 3.4 NS
  Night 117.7 ± 3.0 118.3 ± 4.0NS
  Early morning 112.9 ± 5.2114.1 ± 3.5 NS
 3-h Area above (+) or below (−) baseline, mg ⋅ min ⋅ dl−1
  Afternoon 255 ± 336 −2,690 ± 483<0.005
  Night 527 ± 253−4,424 ± 567 <0.0001
  Early morning−739 ± 510 −3,404 ± 569 <0.04
Insulin secretion rates
 Baseline level, pmol/min
  Afternoon 191 ± 23 196 ± 24NS
  Night 205 ± 25 221 ± 42NS
  Early morning 153 ± 17184 ± 28 NS
 3-h Area above (+) or below (−) baseline, pmol
  Afternoon 1,580 ± 2,372−14,417 ± 3,672 <0.02
  Night1,756 ± 1,755 −17,218 ± 2,898 <0.002
  Early morning 3,030 ± 2,040−13,649 ± 2,754 <0.02
  • Data are means ± SE.